Inspection device



Sept. 23, 1952 HARTMAN 2,611,876

INSPECTION DEVICE Filed Jan. 17 1951 HI K INVENTOR.

ROBERT B.HARTMAN BY 34 2/. m

ATTORNEYS Patented Sept. 23, 1952 INSPECTION DEVICE Robert B. Hartman, Fairfield Conn, assignor to Remington Arms Company, Inc., Bridgeport, I

. Conn., a corporation of Delaware Application January 17, 1951, Serial No. 206,487

2 Claims.

This invention relates to a detector or inspection device for ascertaining the presence of a pulverulent material in a line through which such material is being delivered, and to devices activated in the absence of an adequate quantity of material in the delivery line to perfom any desired function.

The invention is particularly useful in conjunctionwith pulverulent materials which tend to dust and to deposit a dust-coating on surfaces with which they come in contact. The specific embodiment to be described is designed for use in conjunction with the delivery of propellent powder to a machine for loading small arms ammunition, such as shot shells. For this purpose, ordinary visual inspection devices, such as transparent sections in the powder feed line, are unsatisfactory for the reason that, being constantly in contact with the powder moving past them, they very quickly become coated with an opaque dust, and are thus rendered useless.

The present invention contemplates aconstruction in which transparent members are so positioned with respect to the flowing pulverulent material that they are not contacted by the material, and thus retain indefinitely their transparency and their usefulness for the purpose of either visual or photoelectric inspection.

In the drawings:

Fig. 1 is a perspective view of an inspection cell made in accordance with a preferred embodiment of the invention. The figure includes a diagrammatic showing of photoelectric devices working in conjunction with the cell.

Fig. 2 is a fragmentary sectional elevation, substantially on the line 2-2 of Fig. 1.

Pulverulent material is delivered to the inspection cell through an inlet tube It, and escapes therefrom through an outlet tube H, said tubes being joined to the cell through suitable connector blocks 12 and [3 which may be integral with the cell body. The particular cell which is illustrated is of flat rectilinear configuration, comprising a horizontally disposed top plate 14 and vertically disposed side walls [5, I5 joined to or integral with inclined and converging bottom walls [5, It, the outlet I I being at the point of convergence. The frame formed by the top, side and bottom walls is closed at the back with a plate 11. Side walls and back plate may be made of any desired material; for the purpose of handling propellent powder, a non-sparking metal, such as brass, is preferred. The front of the cell is closed by a plate 18 which is of a transparent material, such as glass or Lucite. Plates I! and 18 are secured to the frame in any suitable manner. For the handling ofpropellent powder,

preferably one or more apertures [9 are formed" in the top plate I4 andare closed by loosely. fitting blow-out plugs 20. Withinthe cell and extending between the front and back plates I8 and I1 is a wedgeor cone-shaped fiow-controlling bafile 22, the apex or ridge of which is pref-.- erably located directly below the center of the inlet tube It. The surfaces of the baffle extend outwardly and downwardly from said apex," and their lower margins together with the sloping Walls l6, l6 and the front and back plates'form two restricted passages through which the ma-. terial flows. The inclination of the baffle surfaces is determined by'the character of the particular material being handled. 'For propellent powder; an inclination of about 45 has been foundadesirable.

Near the top of the vertically disposed end walls 15, I5 are apertures'23; 24 which are-closed: by sheets of transparent material. 25, 26, such as glass or Lucite. In the embodiment illustrated; thesetransparent'sheets :or windows have'been shown in juxtaposition to the inner surfaces of walls l5, l5 and extend through slots in the transparent front wall l8 and opaque back wall I! respectively. The windows are capable of sliding movement through such slots, their movement being limited by suitable stops 21, and are of such length as to enable manual cleaning of the entire window from outside the cell.

Fig. 1 shows the configuration assumed by a pulverulent material in its normal flow through the inspection cell. Bodies of such material of a depth not materially exceeding the width of the passages between the margins of the bafile and the inclined walls lie and flow along such walls. Above the baffle the material is arranged in two diverging masses with free upper surfaces extending downwardly and away from inlet I0 at an angle determined by the'angle of repose of the material. These free surfaces terminate near the bottom of the vertical end walls l5, l5 and some distance below the lower margin of the windows 25, 26. The windows are thus completely out of contact with the material, and do not become obscured by a coating of adherent dust which inevitably accumulates on a surface with which a pulverulent material susceptible to dusting is in sliding contact. Experience has shown that even the adjacent corners of the transparent front plate 18 and the mid-portion thereof beneath baflle 22 which are out of contact with the material remain transparent for long periods,

whereas the surfaces of this plate along which the material flows very quickly acquires a dust coating which destroys their transparency.

The bafile is, even under normal operating conditions, a material aid in securing a flow of material through the cell while keeping the upper and outer corners of the cell empty and dustfree. It'scimportance isincreased inthe event that withdrawal of the material from the cell is temporarily diminished or stopped. Vibration incident to the motion of contiguous machinery materially reduces the angle of repose ofrthe material, tending to fill the normally empty upper corners of the cell. Under,extremeconditions; these corners may be completely filled; but, when withdrawal of material from the cell is resumed, such material must: necessarily move through the passages defined by the lower ends of the baffle. The uppencorners of thecell are thus very quickly emptied and the material rethe' upper corners of. the. front plate- The inven- L tion: contemplates. the automatic performance of aiunction suchcas .stoppingithezloading machine or supplying 'a. visual; or audible signalv in the event-.thatimaterial. ceasesit'o flow into: the cell. F01: this :purpose; asourceoftlight illustrated dia' grammatically" at 3:1 is. placed. adjacent window lfilland .a: photoelectric. cell. diagrammatically shownr. 32 placed; adjacent window 25. Aslong assmaterial.isflowingrthroughthe cell, as illustratediinxEigl' 1, .the-.light:from light source Sh'isscut cit iby'tsuch material;. but when the. cell begins tmempty'ra; light path: is established: betweenzthei windows: and to photoelectric cell 32 which is thereby activated. The activation. of the: photoelectric: cell' may, by' conventional meams,:stop ;the: machine .to' which: the. material isizrheing fed,..r:or perform: anyother desired functiom.

'ltzwill heunderstood that the embodiment of theeinvemion; above described andillustrated. in

. 4 the drawings is merely illustrative and typical, and that the device may assume other configurations and is otherwise susceptible to many modifioations, all falling within the scope of the appended claims.

What is claimed is:

l. Apparatus for the delivery of a pulverulent material comprising a; vertically .disposed tubular passage, an inspection cell in said passage having intake and outlet openings, said cell comprising parallel planar vertically disposed walls spacedby a distance substantially greater than the diameter of said tubular passage and inwardly' anddownwardly inclined walls below said vertical Walls, a flow-controlling baflle in said cell, said b'afiie comprising end margins defining passagesand upwardly converging surfaces meeting in a ridge disposed in alignment with said intake'opening, an aperture in and adjacent the top of each of said vertically disposed walls, and photoelectric-means mounted adjacent said vertical walls to transmit a beam of light through one of :said aperturesin the direction of the other of i said :apertures;

2;.Apparatus.accordingito claim: 1, in which each-of; said. apertures is covered by a sheetoi.

transparent material extending outside. said. cell and. supported: for translational. movementiin saidccellina plane: paralleLtotheplane of the aperturediwall.

ROBERTB. HARTMAN .1

REFERENCES CITED The following references are of record in the file of'thispatentt' UNITED STATES. PATENTS Michel .Sept. 24:, 1946. 

